The phrase "a scream and an outrage" describes Nico Muhly's ideal evening at home. Showcasing the musicians and ideas that populate his daily life, Muhly's weekend festival sought to bring a living-room spirit to the Barbican: as he put it, "making a mess of its pristine spaces". Sadly, he succeeded.

The final day began tidily enough, with the Sixteen in glorious form singing Tallis, Byrd, and Pärt alongside Muhly's nicely turned motet I Cannot Attain Unto It and James MacMillan's skilful Miserere setting. Woven into the concert were the first four of Philip Glass's recently completed set of piano Etudes, and much of the day's subsequent two concerts were devoted to the remaining 16 – a world premiere, in effect, with Glass himself taking four of the older ones and Muhly, Huw Watkins and Timo Andres handling the rest.

Only the final Etude, distinctly Schubertian in flavour, touched on genuine enchantment. Two or three more bore traces of inventiveness and lightness of touch. But whether performed beautifully by Andres, brilliantly by Watkins, lovingly by Muhly or endearingly by Glass himself, all artistry was mercilessly trampled over by the grinding gear-changes and endless, artless cadential sequences. As with any three-hour marathon, a fragile euphoria clung to the survivors.

There was plenty to disappoint elsewhere, too, particularly Valgeir Sigurðsson's promisingly titled Architecture of Loss. Muhly's own let's-mess-about-as-if-we're-at-home contributions rather wasted the assembled talent and rapt attention of a sellout crowd.

Two fabulous pieces – a mesmerising and beautifully sustained percussion quartet by Daníel Bjarnason and a string quartet by Joby Talbot, whose galloping melodic lines slipped out of the percussive writing as if by centrifugal force – held a sense of outrage at bay, but the screams will haunt me a while yet.

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